Native Plants

Plains Milkvetch

Astragalus gilviflorus var. purpureus

USDA symbol: ASGIP

perennial forb

Lower 48 states: native

If you’re looking to add authentic Wyoming character to your native plant garden, meet the plains milkvetch (Astragalus gilviflorus var. purpureus). This perennial wildflower might not be the showiest plant in the garden center, but it’s got something special that makes it worth considering for dedicated native plant enthusiasts. Plains ...

Plains Milkvetch may be listed as rare in your area.
Global Conservation Status

Status: S5T2 | Secure: At low or no risk of extinction in the area due to an extensive range, abundant populations, and with little to no concern of declines or threats.

Plains Milkvetch: A Hidden Gem for Wyoming Native Plant Gardens

If you’re looking to add authentic Wyoming character to your native plant garden, meet the plains milkvetch (Astragalus gilviflorus var. purpureus). This perennial wildflower might not be the showiest plant in the garden center, but it’s got something special that makes it worth considering for dedicated native plant enthusiasts.

What Makes Plains Milkvetch Special?

Plains milkvetch belongs to the legume family, which means it has a secret superpower: it can actually improve your soil by fixing nitrogen from the air. Think of it as nature’s fertilizer factory, working quietly underground while adding authentic prairie character to your landscape.

This native perennial is exclusively found in Wyoming, making it a true regional treasure. If you live in the Cowboy State and want to create a garden that truly reflects your local ecosystem, this is exactly the kind of plant that belongs in your native plant palette.

  • Species observed
  • No observations

A Word of Caution: Rarity Considerations

Here’s something important to know: plains milkvetch has a conservation status that suggests it’s not particularly common in the wild. This means if you decide to grow it, you’ll want to source your plants or seeds responsibly from reputable native plant nurseries rather than collecting from wild populations. Think of yourself as a conservation gardener, helping to preserve this unique Wyoming native for future generations.

Is Plains Milkvetch Right for Your Garden?

This plant is best suited for gardeners who are passionate about authentic native landscaping and don’t mind working with species that require a bit more patience and care. It’s perfect for:

  • Prairie restoration projects
  • Authentic Wyoming native plant gardens
  • Naturalized areas where you want true local character
  • Gardeners interested in supporting local ecosystems

Growing Plains Milkvetch Successfully

Since specific growing information for this variety is limited, your best bet is to mimic the conditions where it naturally thrives in Wyoming’s landscapes. As a native prairie plant, it likely prefers:

  • Well-draining soils (most prairie plants hate wet feet)
  • Full sun conditions
  • Low to moderate water once established
  • Minimal soil amendments (native plants often prefer lean soils)

Finding Plains Milkvetch

Because this is a regionally specific and somewhat uncommon variety, you’ll need to do some detective work to find it. Contact Wyoming native plant societies, university extension programs, or specialized native plant nurseries. Don’t be surprised if it takes some patience to locate – the best native plants often do!

The Bottom Line

Plains milkvetch isn’t for every gardener, but it’s perfect for those who want to create truly authentic Wyoming landscapes while supporting plant conservation efforts. If you’re the type of gardener who gets excited about growing something genuinely local and meaningful, this little legume might just become one of your favorite discoveries.

Remember, when you plant natives like plains milkvetch, you’re not just gardening – you’re participating in preserving your region’s natural heritage, one plant at a time.

Astragalus gilviflorus var. purpureus is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Astragalus gilviflorus var. purpureus is also known as:

Orophaca triphylla Isely var. purpurea | USDA symbol: ORTRP

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Rosidae
Order: Fabales
Family: Fabaceae Lindl. - Pea family
Genus: Astragalus L. - milkvetch

Species: Astragalus gilviflorus Sheldon - plains milkvetch

Variety: Astragalus gilviflorus Sheldon var. purpureus Dorn - plains milkvetch

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA